As far as the overwhelming response...not to burst any bubbles but from what I've seen you may or may not get such a response off of a first mailing of just 650 pieces.

For my projects, I would like to tell my GC what types of things I'd like installed like a beautifully designed double vanity sink I found at Lowe's.

I'm working with the contractor to figure out the re-design. 

I don't want to overpay for a new house to raise a family in, especially if we're experiencing a bubble.  

On the marketing side of things, I have some experience with graphic design and advertising.

I myself am an architectural designer with over 30 years experience building so they are a perfect fit for me and they have deep pockets so I can go after bigger deals.

You may also want to hire a painter (depending on the amount needed and the complexity of the space).I've done quite a bit of that and think I finally have a good idea of where i want to go with the design.

Few things, just coming from a designers aspect.

If you have a truss roof, it may not be (though the truss may have been designed to need support).

There could also be other types of designations and use permits depending on the date of the current zoning ordinance.